Obviousness

Obviousness Analysis under 35 U.S.C. § 103 for US12004262

This analysis identifies combinations of prior art references that would render the claims of US12004262 obvious to a person having ordinary skill in the art (POSA). The motivation for combining these references is rooted in the continuous drive within wireless communication to improve efficiency, reduce interference, and support high-density network deployments, particularly within the evolving IEEE 802.11 standards. A POSA in wireless communication, specifically IEEE 802.11 technologies, would have knowledge of MAC and PHY layer specifications, various communication standards (e.g., 802.11a/b/g/n/ac/ax), techniques for managing channel access, power saving, and interference mitigation.

US12004262 generally relates to wireless communication methods and terminals using a Basic Service Set (BSS) identifier, particularly a "BSS color," for triggering uplink transmissions and managing spatial reuse in dense wireless LAN (WLAN) environments. The patent describes a base wireless communication terminal (e.g., an Access Point or AP) that generates and transmits a trigger frame within a Physical Layer Protocol Data Unit (PPDU) to initiate uplink transmission-based random access from other wireless communication terminals (e.g., stations or STAs). A key aspect is the use of a BSS color in the PPDU or trigger frame, especially when triggering transmissions from unassociated STAs.

Combination 1: WO2015120488A1 in view of US10972962B2 and WO2017030342A1

References:

• WO2015120488A1 (Liu et al.): This patent application, published August 13, 2015, discloses a method for identifying a source BSS in WLAN. It describes a High Efficiency (HE) AP sending a packet containing a BSS color to an HE station, and an assigned Association Identification (AID) (including at least part of the BSS color information) to a Very High Throughput (VHT) station. The VHT station then sends a packet containing this BSS color information, allowing other devices to identify its BSS. Liu et al. explicitly mention BSS color being introduced in IEEE 802.11ah for BSS identification, and its use for spatial reuse in dense network scenarios. It also discusses the ability to identify uplink traffic using partial AID which is basically partial BSSID.
• US10972962B2 (Patil et al.): This patent, titled "Signaling identifiers for multiple basic services sets (BSS)", discusses the use of Multiple BSSIDs and the communication between APs and STAs in WLANs, with each BSS being associated with a BSSID. It mentions that an AP can establish common service settings and that STAs can establish wireless associations with an AP.
• WO2017030342A1 (LG Electronics Inc.): This document, published in 2017, describes methods for uplink multi-user (UL MU) transmission in a WLAN system. It details receiving a DL MU PPDU containing a trigger frame with trigger information for UL MU transmission, and then transmitting a UL MU PPDU based on this information. The trigger frame can be a unicast or broadcast trigger frame, configured in a unified format including a common information field and a user information field, which may contain resource unit allocation information.

Motivation for Combination:
A POSA would be motivated to combine the teachings of Liu et al., Patil et al., and LG Electronics Inc. to enhance spatial reuse and efficient uplink resource allocation in dense WLAN environments. Liu et al. introduce BSS color as a mechanism for BSS identification to improve spatial reuse and identify packets from overlapping BSSs (OBSSs), which is crucial in dense networks. Patil et al. reinforce the concept of multiple BSSIDs and the management of BSSs by an AP. LG Electronics Inc. provides a mechanism for triggering UL MU transmissions using trigger frames with common and user information fields, including resource allocation.

The motivation would be to integrate the BSS color mechanism into the trigger frame-based UL MU transmission framework to enable more efficient channel access and interference management. By including BSS color information in the trigger frame, particularly for unassociated stations, the system can improve its ability to perform spatial reuse and make informed decisions about channel access, even for devices not yet fully integrated into a BSS. This would address the problem of efficient resource allocation and interference reduction in dense environments, which is a continuous concern in IEEE 802.11 evolution.

Obviousness Argument:
US12004262 claims a method where a base wireless communication terminal generates a trigger frame for uplink transmission-based random access and inserts it into a PPDU. The PPDU is transmitted using a format including a field indicating a BSS color. Specifically, when triggering random access of a wireless communication terminal unassociated with the BSS, the BSS color is inserted into the trigger frame (e.g., in a User Info field or Common Info field).

• Trigger Frame for Uplink Transmission-Based Random Access in a PPDU: LG Electronics Inc. clearly teaches transmitting a DL MU PPDU comprising a trigger frame including trigger information for UL MU transmission, and subsequently transmitting a UL MU PPDU based on this information. This directly covers generating a trigger frame for triggering uplink transmission and inserting it into a PPDU for transmission. The concept of random access based on trigger frames is also known in IEEE 802.11ax.
• PPDU Format Including a Field Indicating a BSS Color: Liu et al. explicitly disclose an HE AP sending a packet containing a BSS color to an HE station, and also note that N bits can be allocated as BSS color bits (BCB) in HE-SIG symbols to indicate the BSS color. This demonstrates that including a BSS color field in a PPDU format (specifically HE-SIG symbols, which are part of a PPDU) was known. Furthermore, EP3849157B1, by some of the same inventors as US12004262, mentions a BSS color field in the HE-SIG-A field consisting of 6 bits, indicating an identifier of the BSS corresponding to a terminal that transmitted the corresponding PPDU.
• Inserting BSS Color in Trigger Frame for Unassociated Terminals: Liu et al. teach that a VHT station can send a packet containing BSS color information (derived from an assigned AID that includes BSS color information), allowing any AP or station to determine the BSS the VHT station is in. This shows the concept of a station communicating its BSS identity via BSS color. Patil et al. discuss managing multiple BSSIDs and the association of STAs with an AP. The problem of efficiently handling unassociated stations, especially in dense environments, would naturally lead a POSA to consider how such stations could participate in spatial reuse schemes. Knowing that BSS color is used for identification (Liu et al.) and that trigger frames are used for soliciting uplink transmissions (LG Electronics Inc.), a POSA would find it obvious to include BSS color information within the trigger frame, particularly in the "User Info field" or "Common Info field" (as described in LG Electronics Inc. for resource allocation and common information) when targeting unassociated stations. This would allow these unassociated stations to correctly identify the BSS of the transmitting AP and participate in spatial reuse mechanisms or even differentiate traffic for better channel access, aligning with the objectives of improving efficiency and reducing interference in dense WLANs (as highlighted in Liu et al.). The patent itself defines "unassociated" wireless communication terminal as one that may be unassociated with any base wireless communication terminal, which further underscores the need for such explicit BSS identification in broadcast communications like trigger frames.

Therefore, the combination of Liu et al., Patil et al., and LG Electronics Inc. would render the core claims of US12004262 obvious, as it teaches the essential elements of using BSS color in PPDUs and trigger frames for uplink transmission in a wireless communication system, including for unassociated terminals, to improve network efficiency and spatial reuse.

Combination 2: WO2015120488A1 in view of EP3243292A1 and "An Experimental Study of Triggered Multi-User Uplink Access with Real Application Traffic" (Shao et al.)

References:

• WO2015120488A1 (Liu et al.): As above, teaches BSS color for identifying source BSS, improving spatial reuse, and the inclusion of BSS color information in AIDs for VHT stations.
• EP3243292A1 (Oteri et al.): This patent application, published August 23, 2017, discusses "BSS-Color Enhanced Transmission in WLANs (BSS-CET)." It details how BSS color can be transmitted in the ID field of the SIG-1 field of a packet (preamble) to allow STAs to identify the transmitting BSS, and how BSS color may be placed in TXVECTOR/RXVECTOR parameters. It also mentions adjusting Clear Channel Assessment (CCA) thresholds and transmit power control (TPC) based on BSS color to improve spectral efficiency. Oteri et al. also explicitly refers to IEEE 802.11ax as using BSS color.
• "An Experimental Study of Triggered Multi-User Uplink Access with Real Application Traffic" (Shao et al., 2017): This paper discusses Triggered Uplink Access (TUA) in IEEE 802.11ax, where an AP triggers multiple non-AP stations to transmit simultaneously by broadcasting a trigger frame. The trigger frame contains information about participating stations, allocated resource units, and transmission duration.

Motivation for Combination:
A POSA would be motivated to combine Liu et al., Oteri et al., and Shao et al. to achieve robust and efficient multi-user uplink transmissions, particularly in dense environments where spatial reuse is critical. Liu et al. establish the foundational concept of BSS color for BSS identification and spatial reuse. Oteri et al. further elaborate on the technical implementation of BSS color, including its placement in PPDU preambles and its use in CCA/TPC adjustments for improved spectral efficiency, directly addressing dense WLAN deployments. Shao et al. provide the mechanism of triggered uplink access using trigger frames in 802.11ax, emphasizing the AP's role in coordinating simultaneous uplink transmissions.

The motivation would be to integrate the spatial reuse benefits of BSS coloring into the triggered uplink access mechanism. By explicitly carrying BSS color information within the trigger frames (as discussed by Shao et al.) and PPDUs (as discussed by Oteri et al. and Liu et al.), STAs, including those not yet fully associated, can make better decisions regarding channel access (e.g., adjusting CCA thresholds as per Oteri et al.) and avoid unnecessary deferrals, thereby improving overall network throughput and reducing latency.

Obviousness Argument:
US12004262 claims a method of using a BSS identifier (BSS color) within a trigger frame and PPDU for uplink transmission, including for unassociated stations.

• Trigger Frame for Uplink Transmission and PPDU Format: Shao et al. clearly describes the use of trigger frames by an AP to solicit simultaneous uplink transmissions from multiple stations as a key component of IEEE 802.11ax. The trigger frame is broadcast in a PPDU and includes per-STA information like allocated resource units. This fulfills the aspects of generating a trigger frame for triggering uplink transmission and inserting it into a PPDU.
• BSS Color in PPDU for BSS Identification and Spatial Reuse: Liu et al. and Oteri et al. both teach the use of BSS color for identifying the source BSS and facilitating spatial reuse. Oteri et al. specifically mentions transmitting BSS color in the SIG-1 field of a packet (preamble), which is part of a PPDU, to allow STAs to identify the transmitting BSS. This directly addresses the inclusion of a BSS color field in the PPDU format.
• Inserting BSS Color in Trigger Frame, especially for unassociated STAs: Given that BSS color is used for identifying BSSs and enhancing spatial reuse (Liu et al. and Oteri et al.), and that trigger frames are used to coordinate uplink transmissions (Shao et al.), a POSA would be motivated to include BSS color information in the trigger frames. This would enable all recipient STAs, including those not yet fully associated but still needing to participate in random access or make channel sensing decisions, to correctly identify the BSS of the AP transmitting the trigger frame. This ensures that the benefits of BSS coloring for spatial reuse (e.g., adjusting CCA thresholds as taught by Oteri et al.) can be extended to all STAs responding to a trigger frame, regardless of their association status. The information in the trigger frame (which includes common and user info fields according to LG Electronics Inc. - a generally known concept in trigger frames) would be a logical place to put this BSS identification for broad applicability, especially for random access where association might not be fully established. The "User Info field" in a trigger frame could be configured to carry this BSS color for individual or groups of unassociated STAs, providing a clear link between the triggered transmission and the BSS performing the triggering.

Thus, the combination of Liu et al., Oteri et al., and Shao et al. makes the claims of US12004262 obvious by teaching the use of BSS color within PPDUs and trigger frames to facilitate efficient uplink random access and spatial reuse in WLANs, even for unassociated terminals.

Person Having Ordinary Skill in the Art (POSA)

A POSA in the context of US12004262 would be an engineer or researcher with a bachelor's degree in electrical engineering, computer engineering, or a related field, along with several years of experience (e.g., 3-5 years) in designing, developing, or standardizing wireless communication systems, particularly those adhering to IEEE 802.11 standards. This individual would possess:

• A strong understanding of IEEE 802.11 MAC and PHY layers, including different amendments (e.g., 802.11n, 802.11ac, 802.11ax).
• Knowledge of concepts such as Basic Service Sets (BSS), BSSIDs, Association IDs (AIDs), PPDUs, trigger frames, OFDMA, MU-MIMO, spatial reuse, and carrier sensing mechanisms (e.g., CCA, NAV).
• Familiarity with the challenges of dense WLAN deployments, including co-channel interference (CCI) and overlapping BSS (OBSS) scenarios, and techniques for mitigating these issues.
• An understanding of power saving operations and how they interact with channel access.
• The ability to interpret and apply technical specifications and research papers related to wireless communication standards.

This POSA would be motivated to combine existing technologies to solve known problems in the field, such as improving spectrum efficiency and reducing latency in dense wireless networks. The introduction of BSS coloring in 802.11ah and 802.11ax for interference mitigation and spatial reuse, alongside the development of trigger frames for coordinated uplink access, would be well-known to such a person. The idea of extending BSS identification to various communication scenarios, including those involving unassociated stations or random access, would be a logical progression for this POSA to enhance overall system performance.